The present invention relates in general to new and improved automatic closures and in particular to improvements for providing support for a closure member, such as a door or the like.
Closure members which automatically return to a preferred position are well known in the art. Various types of devices are commonly employed to cause a door to assume such a position, e.g. a closed position. One such device is shown in U.S. Pat. No. 3,384,996 and consists of a stationary cam track on which a cam follower rides. The cam follower is secured to a post which extends through the cam track and is rotatably journaled in a bearing integral with the track. Fastening means secured to the post support the door along a vertical edge and cause it to rotate with the post.
In general, automatic closures of this type provide satisfactory performance when used with relatively rigid closure members. Thus, when a door is moved out of its normally closed position by a person entering the doorway, or by an object pushed through the doorway, the rigidity of the door assures that the doorway is clear for passage as long as torque continues to be applied to the door. Such is not the case however where relatively thin and/or flexible closure members are employed, e.g. where the closure member comprises a single panel made of a flexible sheet of plastic, as may be the case in inexpensive light weight closures. For certain types of closures such panels may be stiff but resiliently flexible. For other closures the plastic sheet may essentially comprise a flexible, limp curtain.
If torque is applied to a flexible closure member to move it out of its normal position, the lack of rigidity will produce flexing in addition to rotation of the member, and in some cases the flexing may result in the closure member not rotating to full open position. Under these conditions, portions of the closure member may continue to block the doorway and provide interference with objects passing through. Thus, additional frictional contact between the object and the closure member will occur and the possibility of damage to the latter will be enhanced.